The invention relates to an air-conditioning system for a vehicle, the system comprising an air-conditioning unit control module for regulating the temperature inside a passenger compartment toward a setpoint temperature, said control module being able to correct the regulation of temperature in the passenger compartment as a function of a value of insolation received in the passenger compartment.
Air-conditioning is becoming standard equipment in present-day vehicles, particularly air-conditioning of the “computer-controlled” type, which allows the user to set a desired comfort level by entering a setpoint into a control module of the air-conditioning unit.
A computer-controlled air-conditioning system such as this needs quickly and accurately to reach the comfort setpoint irrespective of the insolation received through the glazed parts of the passenger compartment, which may convey a significant amount of heat into the passenger compartment.
Some systems, described for example in patent document U.S. Pat. No. 4,760,772, take the received insolation into consideration using an infrared light sensor to compensate for the influence of solar radiation on the thermal comfort experienced by the occupants, and more particularly to take account of the angle of irradiation and the position of the sun above the horizon.
While these systems may prove satisfactory in clear weather, when the sky is overcast (cloudy), the light sensor then delivers the same information regarding the amount of incident radiation as it does in a cloudless sky even though the insolation is lower, particularly in the visible spectrum. This then results in over-compensation of the temperature regulation, which has the effect of the occupants feeling some discomfort, due to the blown air being at too cool a temperature.